SpaceX confirmed Tuesday it plans to launch a rocket and capsule on May 7 in a historic first flight of a private spaceship to the International Space Station.

The new launch date, coming a week later than an initially planned April 30 goal, comes after SpaceX said Monday it needed to complete more testing on its unmanned Dragon capsule. The capsule is due to ride on a Falcon 9 rocket from Cape Canaveral Air Force Station in Florida.

"NASA and the Cape Canaveral Air Force Station have approved SpaceX's request to set May 7th as the target launch date for the upcoming COTS 2 mission," SpaceX spokeswoman Kirstin Brost Grantham told AFP.

On its Facebook page, the company said the spaceship would launch at 9:38 am (1338 GMT).

"We appreciate that SpaceX is taking the necessary time to help ensure the success of this historic flight," NASA associate administrator for human exploration and operations William Gerstenmaier said in a statement.

"We will continue to work with SpaceX in preparing for the May 7 launch to the International Space Station."

SpaceX aims to carry out a fly-by of the ISS and a berthing operation in which the reusable spacecraft, the Dragon, will approach the ISS as the crew aboard the orbiting outpost uses a robotic arm to dock it.

The gumdrop-shaped Dragon capsule will carry 1,149 pounds (521 kilograms) of cargo for the space lab and will also aim to return a 1,455 pounds (660 kilograms) load to Earth, according to ISS program manager Michael Suffredini.

Owned by Internet entrepreneur and PayPal co-founder Elon Musk, SpaceX made history with its Dragon launch in December 2010, becoming the first commercial outfit to send a spacecraft into orbit and back.

SpaceX and several other companies are competing to be the first to operate a private capsule that could tote astronauts and cargo to the ISS, after NASA retired its shuttle program last year.

Russia's Soyuz capsule is currently the world's sole means of transporting astronauts and cargo to the orbiting space station.

Other companies in the private space race include aerospace giant Boeing, the Nevada-based Sierra Nevada Corporation and Washington state-based BlueOrigin LLC.

NASA has channeled $270 million to firms hoping to join the new commercial space race and hopes to foster a billion-dollar industry over the next decade.

In a draft budget submitted to Congress in February, President Barack Obama requested $829 million to develop commercial flights to the ISS, partly to end US reliance on Russian craft to deliver astronauts and re-supply the station.

The privatization of space transport is expected to pave the way for tourism, with British tycoon Richard Branson's Virgin Galactic offering $200,000 reservations for journeys into space.

The company has already taken in $60 million in sales and deposits, with more than 500 individuals -- including Hollywood stars and other multimillionaires -- adding their names to the list.

The prices of the only trips into space so far, which were sold to private individuals traveling on Russian spacecraft, have ranged from $45 million to as much as $150 million.